Caterpillar Aftertreatment Regeneration Device III

An number of developments related to the Cat's ARD have occurred since this topic was visited in February.

First, a patent application by Cat was disclosed in March (US 2010/0071355) that seems to be directly tied to problem of holes developing in the ARD body. The patent application is for a flame deflector that is intended to prevent the flame from touching the body of the ARD and possibly the outlet pipe. It states that the flame from the burner may damage the exhaust pipe. Cat and DOE did a significant amount of work to develop a new material for the ARD body that can withstand temperatures up to 850°C suggesting that in use, the ARD can occasionally produce conditions outside its design and validation limits.

Another development is the filing of a lawsuit in March against Cat, a Cat distributor and a truck dealer by Miller Curtis & Weisbrod LLP of Texas on behalf of three Oklahoma-based trucking companies [http://www.catengineproblems.com]. The suit claims the ARD is major source of problems, breakdowns and productivity loss for truck owners. "ARD head clogging" is mentioned as one problem. Others are invited to join the suit.

Caterpillar Aftertreatment Regeneration Device Images

Yesterday's entry summarized some problems Caterpillar had with their Aftertreatment Regeneration Device (ARD). Below are images of the location of the ARD on a 2007 C13 and a closer view with some of the major components labeled. [Photos: Caterpillar]

Caterpillar Aftertreatment Regeneration Device

The US NHTSA Office of Defect Investigations website makes for interesting reading. Sometimes when I have a few minutes, I like to look through it to see what kind of problems engine/vehicle makers face. Something that caught my eye was a number of recalls related to Caterpillar's Aftertreatment Regeneration Device (ARD). This is the burner that is mounted in the exhaust system of 2007 - 2009 onroad C13 and C15 engines and is used to provide heat to regenerate the diesel particulate filter.

Here are some of the facts from the ODI submissions:

1. On November 15, 2007 Caterpillar became aware of a field failure in a C15, which resulted in noise and floorboard heat during regeneration but no fire. The Caterpillar dealer subsequently identified a hole in the extension pipe. Based on this failure and subsequent analysis, Caterpillar determined that some extension pipes may have incorrect material on the end sections and a groove in the attachment flange. Another extension pipe has not proven to be durable under certain conditions. Three extension pipe part numbers used in a total of 307 engines all installed in Freightliner chassis were involved. These extension pipes may develop a crack or hole which may result in a fire hazard. On November 27, 2007 Caterpillar issued a Safety Recall (07E-100). To remedy the defect, Caterpillar will replace the ARD body, extension pipe (if necessary) and upgrade the software (if necessary).
2. On July 9, 2008 Caterpillar became aware of another field failure that occurred on June 18, 2008, which resulted in a damaged hose, resulting in coolant loss but no fire. The Caterpillar dealer subsequently identified a hole in the extension pipe. Investigations revealed that the extension pipe installed in 668 model year 2007 and 2008 C13 engines was again at fault. The engines had been supplied to a number of OEM customers. On August 13, 2008 Caterpillar issued a Safety Recall (08E-054). The remedy was similar the the 2007 C15 recall.
3. On July 31, 2008 Caterpillar became aware of another field failure, which resulted in heat damaged to wiring and loss of headlights and turn signals. No fire was experienced. The Caterpillar dealer subsequently identified a hole in the extension pipe. Unlike the previous two failures, it was determined that the flame in the ARD adjacent to the wall could cause temperatures to exceed material capabilities and the ARD may develop a hole. Potentially, 1585 model year 2007 and 2008 C15 engines installed mainly in Kenworth and Peterbuilt chassis could be affected. On December 3, 2008 Caterpillar issued a Safety Recall (08E-069). In this case, the ARD body would be replaced and the software upgraded.